Human Rights Watch (HRW) has accused Syrian armed opposition groups of unlawful killings, hostage takings, and other abuses during a military offensive against pro-government Alawite villages in the Latakia Province.

In a report on October 11, the New York-based watchdog said opposition fighters had killed at least 190 civilians and seized more than 200 as hostages during the operation, which began on August 4.

The report said two opposition groups that took part in the offensive -- the Islamic State of Iraq and Sham, and Jaish al-Muhajireen wal-Ansar -- were still holding the hostages, mostly women and children.

HRW said the abuses rose to "the level of war crimes and crimes against humanity" and called the operation a "coordinated, planned attack."

HRW said it had conducted on-site investigations and interviews for the report.